Production and chemical composition of Panicum maximum cv. Mombaça under different levels of potassium

Abstract

The effect of potassium levels (0, 15, 30, 45 and 60 mg of K/dm3) on dry matter (DM) yield and chemical composition of Panicum maximum cv. Mombaça, was evaluated under greenhouse with natural conditions of light and temperature. Potassium fertilization significantly (P

Forage accumulation, tillering and bromatological characteristics of Brachiaria grass under nitrogen fertilization

“…This increase, promoted by the higher availability of N in the soil, favors greater absorption of this nutrient (N) by the plant, providing a higher concentration in the plant tissue, especially in the green foliar tissue (Santos et al, 2010). Since N is considered the main constituent of proteins, their content is consequently increased (Costa et al, 2006). In ruminant nutrition, when the N-fertilized pasture protein is degraded in the rumen, much of the CP fractionation is constituted of NPN (Silva et al, 2009), which favors ammonia synthesis.…”

“…The minimum NDF was 66.9% in the whole plant and 60.49% in the leaves, with N doses of 257.5 and 245.07 kg ha -1 year -1 , respectively. The reduction of forage cell wall components may have occurred due to the higher protein concentration in the forage, especially in the leaves, which contributes to the dilution of cell wall components (Magalhães et al, 2011), reducing cellulose, hemicellulose and lignin content and increasing the fraction of soluble compounds readily available and usable by the animals (Costa et al, 2006).…”

“…This increase can be justified since N strongly interferes in the activation of the meristematic tissues present in the axillary buds (Nabinger, 1996). When deficient, there is an increase in the number of dormant buds, whereas adequate supply allows maximum tillering of the grass (Costa et al, 2006).…”

Algumas considerações sobre o sistema radicular de plantas forrageiras

“…O potássio (K) é o segundo nutriente mais retirado do solo pelas plantas (GODOY et al, 2007;COSTA et al, 2012a). A relevância do K para as plantas decorre de suas diversas funções, onde se citam a melhor eficiência de uso da água, em consequência do controle da abertura e fechamento dos estômatos, maior translocação de carboidratos produzidos nas folhas para os outros órgãos da planta, maior eficiência enzimática (MALAVOLTA et al, 1997;LAVRES JUNIOR e MONTEIRO, 2002).…”

PRODUTIVIDADE DA Brachiaria brizantha cv. MARANDU EM FUNÇÃO DA ADUBAÇÃO NITROGENADA NA AMAZÔNIA OCIDENTAL

“…O nitrogênio é o principal constituinte das proteínas que participam ativamente na síntese dos compostos orgânicos que formam a estrutura do vegetal, com elevada influencia sobre as características morfogênicas e estruturais das plantas (COSTA et al, 2006). Cerca de 80% das áreas de pastagens cultivadas no Brasil são ocupadas por genótipos de Brachiaria, como a Brachiaria brizantha cv.…”